Pick out the correct statement about the condensation.
Filmwise condensation gives a lower heat transfer rate than the dropwise condensation
Suitable coating or vapour additive is used to promote film wise condensation
If a condensing liquid does not wet the surface dropwise, even then condensation will take place on it
Reynolds number of condensing liquid is based on its mass flow rate
Correct Answer :
B. Suitable coating or vapour additive is used to promote film wise condensation
Related Questions
If a solid is compressed adiabatically in its elastic range, its __________ remains constant
Internal energy
Enthalpy
Entropy
Temperature
__________ is the process of coating the surface of steel with aluminium oxide, thereby imparting it increased resistance to corrosion & oxidation upto a temperature of 700°C.
Veneering
Galvanising
Electroplating
Calorising
The approximate height of a blast furnace having a useful volume of 2000 m3 is about __________ metres
25
35
55
75
Specific gravity of hot metal (pig iron) is __________ times that of the blast furnace slag.
2
3
0.8
6
Pick out the wrong statement.
Copper is the metal having the highest electronic conductivity
Hardenability & Weldability of metals are inversely related
Covalent bonding formed by sharing of electrons is present in all semi-conductor materials
Glass transition temperature applies to 'polymers' but not to 'glasses'
The ability of tool steel to resist softening at high temperatures is termed as __________ hardness.
Red
Extended
Super
Extreme
The ratio of the shear stress to the principal stress on a principal plane is
0
1
1/2
1/3
Silicon crystal can be converted to p-type semiconductor by doping with
Phosphorous
Nitrogen
Carbon
Boron
Which of the following is an ore dressing operation?
Classification
Smelting
Roasting
None of these
Stresses encountered in the metal forming processes are less than the __________ of the material.
Fracture strength
Yield strength
Elastic limit
Limit of proportionality
In the X-ray radiography technique, the tube voltage for thicker plates as compared to thin plates, should be
Higher, as it gives higher wavelength
Lower, as it gives higher wavelength
Higher, as it gives shorter wavelength
Lower, as it gives shorter wavelength
A high pressure boiler generates steam at a pressure greater than __________ kg/cm2.
10
30
50
80
The minimum carbon content in steel should be __________ percent for it to respond to a hardening treatment.
0.2
0.4
0.6
0.8
In the formation of cermets, the ratio of ceramic material to metallic material is usually 80:20. Which of the following is a cermet?
Zirconia
Alumina
Bakelite
Tungsten carbide
Lead is poured into the joint between two- __________ pipes.
Mild steel
Concrete
Cast iron
Asbestos cement
Earing is a defect found in steels after the following metal working operation.
Extrusion
Rolling
Deep drawing
Wire drawing
What is the percentage of chromium in 18-4-1 high speed steel?
1
4
18
23
Maximum permissible air velocity in pipelines is about __________ metre/second.
5
10
20
40
__________ test is the appropriate test to determine whether a material is ductile or brittle.
Impact
Cupping
Hardness
Tensile
Methyl orange indicator turns
Orange yellow in alkaline medium
Orange yellow in acidic medium
Colourless in acidic medium
Colourless in basic medium
The best guide to judge the general quality of water is the measurement of its
pH value
Electrical conductivity
Turbidity
Dissolved oxygen content
Galvanic corrosion cannot be prevented by
Cathodic protection
Anodic protection
Usage of largest possible anodic area
Any one of these
Heat transfer by __________ is almost absent in case of fluidised bed drying operation.
Radiation
Conduction
Convection
Both (B) & (C)
Copper deposits are found in India at the following location:
Kudremukh
Kolar
Khetri
Ramagundam
The excess air required for the combustion of pulverised coal is of the order of about __________ percent.
5
15
30
45
Shaft/rotor speed is most accurately measured by a
Frequency counter
Tachometer
Strobometer
Speedometer
Which of the following are considered applications of ultrasonic testing?
Determination of elastic constant
Detection of defects in metal
Measurement of material thickness
None of the above
Which of the following is an example of stress corrosion?
Season cracking of brass
Caustic embrittlement of steel
Both (A) & (B)
Neither (A) nor (B)
If a nuclear reactor produces more fissile nuclear fuel than it consumes, then it is called a __________ reactor.
Critical
Breeder
Fertile
Heterogeneous
Encyclopaedia of Chemical Technology has been
Authored by Kirk Othmer
Edited by Perry and Chilton
Edited by Kirk Othmer
Authored by Perry and Chilton